Transfer article for forming tetroreflective and colored images and method of making same

ABSTRACT

A transfer with durable images comprising a support sheet having a monolayer of transparent microspheres that are partially embedded in the support sheet with a specularly reflecting layer covering the parts of the surfaces of the microspheres which are exposed above the support sheet. One or more coatings of two-component colors can be printed imagewise on top of the layer of microspheres. The two-component colors are based on polyester resin and an isocyanate hardener.

This invention concerns a transfer for decorating surfaces, preferablytextiles or other flexible materials, with images being extremelydurable and capable of standing both hot water wash and dry cleaning. Inparticular the invention concerns a transfer for decorating surfaceswith images comprising light-reflecting areas of any configuration andcolor in arbitrary combination with colored non-reflecting areas. Theinvention also relates to a process of making such transfer.

It is known to decorate textiles by printing patterns in various colorsby a suitable printing method, e.g. the silk screen process. For suchpatterns to be durable in use and to have good fastness to repeatedwashing, it is important that the inks used for the printing have goodadhesion and cannot be peeled or picked off, that they are elastic so asto be capable of following the expansion and contraction of thesubstrate, and that they do not crackle or flake.

So-called plastisol inks have been developed for this purpose, based onelastomeric resins, often modified polyvinyl chloride (PVC), dissolvedin high-boiling organic solvents. These plastisol inks, which are alsocalled gum printing inks, can be given all possible shades bypigmentation.

It is also known to produce so-called transfers by means of theseplastisol inks, i.e. by printing a given pattern in mirror-invertedfashion on a suitable substrate, preferably silicone or wax treatedpaper. The pattern may then be transferred by the user, e.g. a textilefactory, from such a transfer to the textile by application of heat,i.e. the transfer is placed with the inked side against the textile andheated to 130° to 200° C., generally 160° to 180° C., under a pressureof 100° to 800 kPa, generally about 500 kPa, for 10 to 30 seconds,generally 15 to 20 seconds. The temperature, pressure and treatment timeused depend, of course, upon the Type and nature of the textile fabricand upon the plastisol type applied, but generally higher temperatureswill involve treatment for a shorter period of time, and vice versa.

The international patent application published as WO 80/00462 describesa method of applying a metallised and/or pigmented decoration to asurface, for example a garment surface, comprising the steps of firstproviding a conventional ink transfer having the form of the intendeddecoration, and transferring the image therefrom to the surface inconventional manner by application of heat and pressure, and thensuperimposing a foil having a metallised and/or pigmented coating to thesaid image, subjecting the foil to heat and/or pressure to cause it toadhere to the image, and peeling off the foil thereby to provide ametallised or pigmented cover adhering to the image and beingcoextensive therewith. The metallised or pigmented coating on the foilmay optionally be provided with a layer of heat or pressure sensitiveadhesive on the face intended for application to the image, being soselected as to have an affinity for the material of the image and adisaffinity for the surface to which the image is applied. Themetallised and/or pigmented coating may also include a cover layer onthe face opposite the face intended for application to the image. But inany case this so-called "hot split" method only aims at applying ametallised and/or pigmented coating to the entire surface of an imagebeing already transferred conventionally from a known transfer.

It is further known to produce so-called retro-reflecting films with agreat light reflecting capacity for application on e.g. textiles, firstand foremost for security reasons. These retro-reflecting films orreflex films come in two main types, one with a very large number offine glass beads with a high refractive index embedded with a reflectingsubstrate in a base sheet (glass bead type), and another formed with alarge number of prisms in a sheet. Both types may be formed with theglass beads or the prisms exposed in the surface (open type) or enclosedin a transparent layer (semi-open type) or coated with an optionallyinked layer (closed type), or finally encapsulated in closed cavitieswith entrapped air (capsule type). The reflex films may be formed asreflex transfer films with a heat-activated adhesive intended for i.e.heat application to textiles. Reflex transfer films of the glass beadtype may moreover be produced in a very elastic material, which makesthem particularly suitable for application to flexible materials.

It is known from i.e. US patent specification No. 3 836 227 to producesuch a retro-reflecting film of the glass bead type by embedding amonolayer of glass microspheres having diameters between about 40 and 80μm to a depth of about 40% of their diameter in a carrier sheetconsisting of a polyethylene coating on a paper liner with heating ofthe polyethylene to about 140° C. A transparent specular coating of zincsulfide having a thickness of one-quarter the wave length of white lightis vapor-coated onto the exposed surfaces of the microspheres,whereafter the exposed glass microspheres are coated with an aqueousdispersion of a binder material comprising a thermoplasticheat-activatable adhesive copolymer of ethylene, vinyl-chloride andacryl amide and optionally a further thermoplastic heat-activatableadhesive copolymer of methyl methacrylate, ethyl acrylate andmethacrylic acid in sufficient thickness to leave a dried layer whichcompletely covers the microspheres. The layer is dried at 93° C. for 10min. Optionally, a second layer comprising a thermoplasticheat-activatable adhesive copolymer based on acrylic acid and an acrylicacid ester may be applied. The resulting sheet material may be adheredonto a substrate, such as cardboard, by placing the exposed surface ofthe binder layer against the cardboard, and then passing the combinationmomentarily between hot lamination rolls heating the interface of thebinder layer and cardboard to 120-132° C. When the laminate has beencooled to room temperature the polyethylene-coated carrier sheet isstripped away.

It has been a significant drawback in the use of the known reflextransfer films that when applying the reflecting figures and signs, e.g.in the form of letters (words, messages) and logos it has been necessaryto punch or cut out each individual letter/figure and apply themmanually. Even though substantial funds have been invested in computercontrolled cutting machines it has been necessary to remove the excessmaterial around and in the letters manually, which is both labourdemanding and entails heavy material loss. It is another drawback thatpreviously it has only been possible to produce single-colored lengthsof reflex transfer films. True, it is known to print a reflex transferfilm with transparent color over the glass bead surface to obtainvarious patterns and light effects, but this method does not eitherprovide the possibility of producing individual letters/figures withoutthe use of punching or cutting.

An attempt to remedy some of these drawbacks has been made in DK patentNo. 155 888 B (and the corresponding international patent applicationpublished as WO 88/08793) according to which a special plastisol reflextransfer is prepared by a method in which a conventional plastisoltransfer is coated with an elastomer granulate of a type (e.g. based onpolyacryl amide) compatible with the plastisol ink and with the surfacelayer of a reflex transfer film, and the granulate is fused into theplastisol print by heating, following which a reflex transfer film cutto the contour of the pattern is positioned with the reflecting sideinwards against the elastomer treated plastisol print and adhered to itby brief heating under a quite slight pressure. The thus formedplastisol reflex transfer may then be transferred to the desiredsubstrate, in particular a textile, by conventional heat application. Bythis means it is possible to decorate textiles or other, preferablyflexible, materials with patterns consisting of strongly lightreflecting areas delimited by colored areas without having to cut outeach light reflecting detail separately. However, manual work is stilldemanded for punching or cutting out the more regular pieces of reflextransfer film which are coupled onto the conventional plastisoltransfer, and the light reflecting details must at least partially bedelimited by colored areas.

US patent specification No. 4 102 562 discloses a transfer sheetmaterial for forming retro-reflective graphic images on a substrate,said sheet material comprising a support sheet, a dense continuousmonolayer of transparent microspheres partially and removably embeddedin the support sheet to a depth averaging between about one-quarter andone-half of their diameter, a specularly reflective layer covering thesurfaces of the microspheres which are exposed above the support sheet,and a transfer layer printed over the layer of microspheres in animagewise pattern, which leaves areas of the layer of microsphereswithout pattern, the transfer layer being of a thickness such as toembed within it the surfaces of the microspheres that are exposed abovethe support sheet in the printed areas, and the transfer layer beingadhereable to a substrate while retaining its imagewise pattern so thatwhen the transfer layer is adhered to the substrate and the supportsheet is stripped away, the transfer layer is left in place on thesubstrate, with the microspheres pulled from the support sheet andpartially embedded in the transfer layer to form an image which isretroreflective over its full area. It is also stated that the transferlayer consists of a vinyl plastisol ink, and that the specularlyreflective layer on the microspheres consists of a transparentdielectric mirror, but may also, if transparency is not necessary,consist of a vapor-coated metal, such as aluminum. It is further statedthat a thin adhesion promoting layer comprising a polyurethane or asilane may be disposed between the specularly reflective layer and thetransfer layer.

It has however been found that transfer layers of this kind, even whenan adhesion promoting layer is applied between the specularly reflectivelayer and the transfer layer, do not ensure sufficient adhesion of themicrospheres and do not adhere sufficiently to flexible substrates, suchas textiles. Thus it is seen from example 1 of U.S. Pat. No. 4 102 562that a reflecting image transferred onto garment from a transferaccording to that patent specification lost 60% of its retro-flectiveintensity already after 5 washes in an automatic washer using hot water.Besides, images based on vinyl plastisol inks cannot stand dry cleaning.These drawbacks must be the reason why this kind of reflex transfer hasnot been put into practical use since it was invented in 1976.

According to the present invention we have found that it is possible toproduce a transfer for decorating all kinds of textiles with imagesbeing extremely durable and capable of standing hot water wash and drycleaning, using two-component colors and extenders developed especiallyfor printing on difficult materials such as nylon, polyester,polyalkenes and siliconized surfaces. Such two-component colors andextenders have never before been used for producing transfers, as aftersetting they are not heat-activatable and will normally adhere sostrongly to the support sheet (usually silicone or wax treated paper orpolyethylene foil) as to be incapable of letting go again. At the sametime they generally have poor adhesion to ordinary textiles, such ascotton and the like. We have also found that it is possible instead ofthe above mentioned two-component extender to use a polyester-basedglue.

In the broadest aspect the transfer according to the invention comprisesa support sheet having printed imagewise thereon one or more layers oftwo-component colors based on polyester resin and an isocyanate hardenerand, if there is more than one color layer, on top thereof a layer of acorresponding two-component extender or a polyester-based glue, thecolor layer or the extender and color layers containing a polyester orpolyamide based elastomer which has been applied to the color orextender layer while it was still wet, and fused into the color layer orthe extender and color layers.

According to the invention such a transfer is produced by a methodcomprising the following steps:

(a) on a support sheet one or more layers of two-component color basedon polyester resin and an isocyanate hardener are printed imagewise,

(b) if more than one color is printed, each color layer is driedseparately before the next layer is applied, and over all the layers alayer of a corresponding two-component extender or a polyester-basedglue is printed,

(c) while the single-color layer or the extender layer is still wet, apowder of a polyester or polyamide based elastomer is applied, and thepowder is fused into the color layer or the extender and color layers.

It is extremely surprising that by using an elastomer powder which isnormally used to improve the adhesion to textiles of thermoplastictransfer colors, such as conventional plastisol colors, in this specialway according to the invention it is possible to modify setting colormaterials which have been developed for direct printing on difficultsubstrates so as to make them suited for transfers which can beheat-transferred to textiles in usual manner and provide extremelydurable images. When printing a transfer it is also achieved thatwhereas by conventional transfer inks each color layer had to be driedat 160-180° C. for 15-25 seconds before application of the next layer,according to the present invention it suffices to dry each color layerat 50-60° C. for 15-25 seconds. Hereby any shrinkage or crumbling of thesupport sheet is avoided, enabling far more accurate and detailedprinting.

According to this embodiment of the invention the support sheet is aconventional transfer carrier, e.g. a paper liner coated with wax orsilicone or rapid-setting polyurethane.

A unique feature of the present invention thus comprises using as colorand transfer layer in the transfer two-component colors andcorresponding extenders based on polyester and isocyanate hardener,which are normally used for printing on difficult substrates. Examplesof two-component colors and extenders usable for producing the transferaccording to the invention include the color series "Visprox TCI 8700"and the transparent color series "Visprox TCI 8790" with correspondingextender and hardener "TCI 8700 Hardener", which are produced by VisproxB. V., Haarlem, Holland, and the color series "Nylobag NB" and NylotexNX" with corresponding extenders and hardener "NB Catalyst", which areproduced by Sericol Group Limited, Westwood Road, Broadstairs, Kent CT102Pa., England.

Another unique feature of the present invention is the use of apolyester or polyamide based elastomer powder which is applied to thestill wet extender layer and fused into the extender and color layer.The fusing may e.g. be achieved by means of infra-red heating to130-250° C. for 20-30 seconds. It has been found that the transfer basedon two-component colors and extender without incorporation of thiselastomer will soon loose its property for heat activation, but that theincorporation of the elastomer ensures the durability of the transfer,also by long-term storage. It has also been found that the elastomersignificantly increases the adhesion between the transfer and textilesand simultaneously decreases the adhesion of the color and extenderlayer to the support sheet, allowing the latter to be stripped off afterthe transfer of the image to the textile. Examples of elastomer powdersusable for production of the transfer according to the invention includethe polyamide resin powder "FT-409 Transfer Powder", which is producedby Sericol Group Limited, Westwood Road, Broadstairs, Kent CT10 2PA,England, and the polyester resin powder (polydiol dicarboxylate)"Avabond 48E Powder", which is produced by Imperial Chemical House,Millbank, London SW1P 3JF, England.

It has been found that it is possible instead of the layer oftwo-component extender in the transfers of this invention to use a layerof a polyester-based glue such as the one sold by Unitika Sparklite Co.,Ltd., Japan, as a transfer glue designated "TR Glue". The raw materialsfor this glue are:

(A) Crystalline saturated polyethylene terephthalate resin in powderform

    ______________________________________    Melting point:    110° C.    Brand name:       "Vylon GN - 915 P"    Manufacturer:     Toyobo    ______________________________________

(B) Saturated polyethylene terephthalate resin in liquid

    ______________________________________    Composite:     50% saturated polyester resin                   in block                   50% cyclohexanone (solvent)    Viscosity:     5000 centipoise at 20° C.    Brand name:    "Vylon RV - 15 CS"    Manufacturer:  Toyobo    ______________________________________

The transfer glue is prepared by adding A (25% by weight) to B (75% byweight) while stirring the glue, and the finished glue has a viscosityof 90 000 centipoise at 20° C. and a resin content of 62.5% by weight.

Such glues based on saturated polyester do not need a hardener for theirfunction, but they take a somewhat longer time to dry than thetwo-component colors and extenders, for example 3-5 hours in a dryingoven at 50-60° C. or up to several days at room temperature. They can beused without having a polyester or polyamide based elastomer powderfused into the layer, if no special demands for durability andwashability of the decorated textiles are to be met. However, if thetransfers are to be used for work clothes and/or the textiles decoratedtherewith must endure washing at temperatures above 50° C., it isadvisable to cover the glue layer with an elastomer powder which isfused into the layer as described above.

According to the invention it has also been found that the saidtwo-component colors and extenders in connection with the specialtreatment according to the invention are usable as transfer layer inreflecting transfers and provide solid anchoring of the reflecting glassbeads in the layer and a firm adhesion to the substrate onto which thelayer is transferred, so that the image transferred stands both wash anddry cleaning. Here, too, a polyester-based glue may be used instead ofthe two-component extender. In this connection it has also been foundpossible by use of a release agent in a simple printing process toachieve that the produced transfer comprises both reflecting andnon-reflecting areas.

According to the invention it is thus possible by simple graphicprocesses to produce transfers for decoration of textiles with imagescomprising light reflecting areas of arbitrary configuration and colorand in arbitrary combination with colored non-reflecting areas, saidimages being durable and preserving their reflective intensity both inwash and dry cleaning.

This is achieved by the transfer according to the invention whichcomprises

(a) a support sheet with a monolayer of transparent microspheres beingpartially embedded in the support sheet to a depth of between aboutone-quarter and one-half of their diameter,

(b) a specularly reflecting layer covering such parts of the surfaces ofthe microspheres as are exposed above the support sheet,

(c) optionally a coating of a release agent printed imagewise on top ofthe layer of microspheres at places where a non-reflecting image isdesired,

(d) one or more coatings of two-component colors based on polyesterresin and isocyanate hardener as well as various pigments printedimagewise on top of the layer of microspheres and release agent, if any,

(e) a transfer layer of an extender corresponding to the two-componentcolors, but without pigment, or of a polyester-based glue printedimagewise on top of the layer of microspheres and color in suchthickness that the exposed parts of the glass beads above the supportsheet are completely embedded therein,

(f) the extender and color layers containing a polyester or polyamidebased elastomer which has been applied while the extender layer wasstill wet, and fused into the extender and color layers.

The method according to the invention for producing such a transfercomprises the following steps:

(a) a support sheet with a monolayer of transparent microspheres beingpartially embedded in the support sheet to a depth of between aboutone-quarter and one-half of their diameter, is coated with a specularlyreflecting layer covering the surfaces of the microspheres that areexposed above the support sheet,

(b) if parts of the transferred image are not to be reflecting, acoating of a release agent is printed imagewise on top of thecorresponding parts of the layer of microspheres,

(c) one or more coatings of two-component colors based on polyesterresin and an isocyanate hardener as well as various pigments are printedimagewise pattern on the layer of microspheres and optionally releaseagent, and each color coating is dried,

(d) a transfer layer of an extender corresponding to the two-componentcolors, but without pigment, or of a polyester-based glue is printed onthe layer of microspheres and color in such thickness that the exposedparts of the glass beads above the support sheet are completely embeddedtherein,

(e) while still wet the extender layer is coated with a powder of apolyester or polyamide based elastomer, and the powder is fused into theextender and color layers.

The support sheet with a monolayer of transparent microspheres used inthe present embodiment of the invention may be a glass bead releasesheet of the kind produced in the first step of the production processof the known reflex transfer foils of the glass bead type. The carriermay e.g. by a paper liner or a polyester foil provided with a coating ofthermoplastic material, e.g. polyethylene, being sufficiently thick tobe capable of embedding the glass beads to a depth averaging betweenone-quarter and one-half of their diameter. Advantageously, thethermoplastic material is coated with an agent, such as silicone, whichcontrols the adhesion of the glass beads to the material. Then amonolayer of glass beads is applied by heating of the support sheet tosoften the thermoplastic material so as to ensure embedding of the beadstherein.

The specularly reflecting layer which is applied to the exposed parts ofthe glass beads may in known manner consist of a transparent dielectricmirror or, if transparency is not needed, metal, such as aluminum. Ifthe reflective intensity is of no decisive importance the glass beads donot need to form a dense continuous layer, but may be applied to thesupport sheet in reduced density, so that the color or colors in thefinished image are visible between the beads, even if the beads arecoated with aluminum.

A special feature of the present invention is the optional applicationof a coating of a release agent on parts of the layer of glass beadsbefore the application of the color and extender layer. This releaseagent must be of such nature that the glass beads applied thereto let gomore easily of the color and extender layer than of the support sheetwith optionally applied silicone coating. Hereby it is achieved thatwhen the transfer-image has been transferred to a substrate by heatactivation the glass beads when peeling off the support sheet willremain adhered in the color and extender layer except in such areaswhere they have been coated with a release agent. The release agent maye.g. be a silicone or a fast setting polyurethane. A suitable releaseagent is a silicone of the type "Dispersion CAS 4A' 75%" sold by RhonePoulenc.

One of the significant advantages of this embodiment of the invention isthat it is possible by imagewise printing with release agent to decidewhich parts of the transfer pattern must be reflecting and then byimagewise printing with several colors of the above stated kind in eachseparate printing process to form a multicolor transfer pattern. Aftereach of these printing processes the applied coating is dried in air atfrom room temperature up to max. about 60° C. for from 5 min to 10seconds, preferably 50-60° C. for 15-25 seconds. By another imagewiseprinting process the color coatings and any further areas which it isdesired should be colorlessly reflecting are coated with a layer ofextender, and while this layer is still wet it is covered by anelastomer powder of the previously stated kind, and the powder is fusedinto the extender and color layers by heating to 130-250° C. for 10-40seconds, preferably to about 180° C. for about 20 seconds. Thus, merelyby repeating simple graphic printing processes it is possible to producetransfers with which, by conventional application of heat, amulti-colored image having reflecting and nonreflecting areas in anydesired configuration may be transferred.

If, however, an image having only one color is desired the extender orglue layer may optionally be left out and the color be used also asbinder and transfer layer, the color being applied in a sufficientlythick layer for the exposed parts of the glass beads above the supportlayer to be completely embedded therein, and, while the color layer isstill wet, applying the elastomer powder and fusing it into the colorlayer as stated above.

On the other hand, it is also possible to leave out the color coatingsand the optional coating of release agent printing the layer oftwo-component extender or polyester-based glue imagewise directly on thelayer of microspheres so that the transfer image only comprisesuncolored reflecting areas.

Instead of using the usual printing processes, e.g. silk screenprinting, it is also possible to use a color copier with two-componenttoner for applying the color coatings. When using several colors all thecolors can thus be applied in one working operation. In any event thecolor coating must subsequently be covered with a layer of colourlesstwo-component extender which while still wet is covered with anelastomer powder of the previously stated kind, which is fused into thelayer. A suitable color copier could e.g. be "Canon Color Laser Copier500" which operates with indirect electrostatic copying in full color orsingle color generated by toner projection with two-component toners inthe colors yellow, magenta, cyan and black or one of these and withfixation by passage of hot rollers. This laser color copier is producedby Canon Inc., 2-7-1 Nishi-Shinjuku, ShinJuku-ku, Tokyo 163, Japan.

Transfers according to the invention may advantageously be produced inlarge scale on so-called roll to roll transfer machines.

Such machines normally operate with a silicone paper provided in largerolls with a width of as much as 90 cm. The paper passes continuouslyfrom one silk screen printing machine with subsequent drying oven toanother. Thus, if four stations are available 4-colored transfers may beproduced. The transfer is cut from the finished roll.

In the reflex-transfer embodiment the reflex-liner in the roll format isused as support, and the last printing station is used for printing theextender layer, which subsequently in a wet state passes through apowder application unit which applies the elastomer powder. Fusing issubsequently performed in an infra-red drying oven. Times andtemperatures are as in normal transfer production.

It is also possible to transfer the transfer pattern continuously from athus produced transfer roll to lengths of textile. Use can be made ofknown technology from the so-called sublistatic method in which patternsare transferred in a continuous calander-process from a colored paper tolengths of textile by means of heat and pressure in a continuousprocess. The transfer machine can be adjusted with temperature,pressure, time corresponding to the normal application conditions fortransfers of the present type.

Hereby it is possible to produce reflecting patterns which could not beobtained rationally by separate applications of reflex transfers.Consequently new design possibilities may be offered to the clothingindustry.

BRIEF DESCRIPTION OF THE DRAWINGS

The support sheet used was a sheet material produced as described in USpatent specification No. 4 102 562, column 3, line 33-53 and comprisingthe parts 1, 2, 3 and 4 shown in the attached drawing. The sheetmaterial comprises a Kraft-paper base sheet 1 covered with athermoplastic layer 2 of low-density polyethylene, in which transparentglass microspheres 3 have been embedded by heating, the microsphereshaving a refractive index of approx. 1.92 and diameters in the range of70-100 μm. On the parts of the microspheres 3 which are not embedded inthe polyethylene layer 2, they are provided with a transparentdielectric mirror 4 consisting of a vapor-coated layer of cryolite andon top of this layer a vapour-coated layer of zinc sulfide, each layerhaving an optical thickness (the product of physical thickness andrefractive index) of one-quarter the wave length of white light, i.e.approx. 140 nm.

In a silk screen printing machine the following layers are printed in animagewise inverted fashion on this support sheet:

1. On such areas of the support sheet intended to give a non-reflectingtransfer-image is printed a clear varnish layer consisting ofrapid-setting polyurethane, and this layer is dried in an infra-redjet-drying oven at approx. 60° C. for 60 seconds, whereafter thepolyurethane is no longer heat-activatable, but forms a solid bond withthe support sheet and binds the glass beads thereto. Simultaneously thevarnish layer has a hard and smooth surface which does not react withthe subsequent two-component colors and extender, and it consequentlyacts as a release layer towards these layers.

2. On top of the glass beads and the release layer the desired colorlayers, denoted by 5 in the drawing, are then, each in a separateworking operation, printed with two-component colors selected from thecolor series "Nylotex NX" admixed with 1-5% (v/v) hardener "NB Catalyst"produced by Sericol Group Limited. After each printing the color layeris dried in an infra-red jet-drying oven at approx. 60° C. for approx.20 seconds.

Over all these color layers and optionally beyond them, if the transferimage is also to comprise uncolored reflecting areas, is printed a layerof "Nylotex NX" extender base, corresponding to the colors, but beingwithout pigmentation and consequently transparent, in a thickness whichcompletely embeds the exposed parts of the glass beads (40-75 μm afterdrying) denoted by 6 in the drawing.

While the extender layer is still wet it is covered with a powder of apolydiole dicarboxylate elastomer, "Avabond 48E Powder", produced byImperial Chemical House, denoted by 7 in the drawing. The powder sinksinto the extender layer and by immediately succeeding heating in aninfra-red oven at 180° C. for 20 seconds the elastomer powder is fusedwith the extender and color layers. The result is a finished transferaccording to the invention.

The transfer image is transferred to a textile ofpolyester/cotton-mixture by positioning the transfer with the powdertreated extender layer against the textile and introducing thecombination in a heat press exerting a pressure of 310 kPa at atemperature of 160° C. for 12 seconds. After cooling the support sheetis peeled off whereby the glass microspheres remain on the patterntransferred where they are anchored in the color and extender layers,whereas they adhere to the support sheet at such places where a releaselayer has been interposed and on the excess part around the transferpattern.

The transferred image shows a design consisting of non-reflecting areasin the desired colors and also reflecting areas where the glassmicrospheres provide a strong retro-reflex in darkness, but in daylightpermit the light to shine through and reproduce the underlying colorswith a glittering glow. The image adheres extremely well to the textileand endures both hot water wash (95° C.) and dry cleaning withdichloroethylene and similar agents.

We claim:
 1. A transfer for placing a retroreflective article on asubstrate, which transfer comprises:(a) a support sheet; (b) a monolayerof transparent microspheres embedded about one-fourth to about one-halftheir diameter in the support sheet; (c) a specularly reflecting layerdisposed on the portion of the microspheres that protrudes from thesupport sheet; and (d) an imagewise coating applied over the specularlyreflecting layer, the imagewise coating being based on a polyester resinand an isocyanate.
 2. The transfer of claim 1, wherein the specularlyreflecting layer is a transparent dielectric mirror and the imagewisecoating is colored.
 3. The transfer of claim 2, further comprising anextender layer that covers at least the imagewise coating, the extenderlayer being based on a polyester resin and an isocyanate.
 4. Thetransfer of claim 3, further comprising a polyester or polyamide basedelastomer that is fused into the extender layer.
 5. The transfer ofclaim 1, further comprising a release agent disposed between thespecularly reflecting layer and the imagewise coating, the release agentallowing the microspheres to remain in the support sheet in areas wherethe release agent is disposed after the support sheet is separated fromthe transfer.
 6. The transfer of claim 5, wherein the specularlyreflecting layer is a metal layer and the imagewise coating is colored,and when the support sheet is separated from the transfer to form aretroreflective article, the color of the imagewise coating is visiblefrom the front side of the retroreflective article in areascorresponding to where the release agent was disposed.
 7. The transferof claim 5, wherein the imagewise coating is colored, and the transferfurther comprises an extender layer that covers the imagewise coatingand the specularly reflecting layer in such thickness that themicrospheres are embedded therein.
 8. The transfer of claim 7, whereinthe extender layer is based on a polyester resin and an isocyanatehardener or is based on a polyester based glue.
 9. The transfer of claim8, wherein the extender layer is based on a polyester resin and anisocyanate hardener.
 10. The transfer of claim 7, further comprising asecond imagewise colored coating applied on the specularly reflectinglayer, the extender layer also covering the second imagewise coloredcoating.
 11. The transfer of claim 10, wherein the extender layer isbased on a polyester and an isocyanate.
 12. The transfer of claim 11,further comprising a polyester or polyamide based elastomer that isfused into the extender layer.